Regarding Delay function

Hi,

Suppose if I want 5 Sec Delay
What is the value I need to keep in the function DELAY_US(uSec)

You should pass 5000000 value for 5 Sec delay

like DELAY_US(5000000)

-Aditya

Hi,

then the calculation would be [((5000000*1000*(10^6))/(16.67*(10^6)))-(9*(10^6))]/[5*(10^6)].

This value how it will be equal to 5 Sec.

The above calculation will provide the LoopCount for the Delay function called in ...usDelay.asm file.

When you pass 5000000 value  for DELAY_US macro, the value will convert to LoopCount value for Delay function called in ...usDelay.asm file.

For LoopCount calculation,

Along with 50000000, CPU_RATE will be considered. CPU_RATE is based on your target device

For one of the target, the ...usDalay.asm file looks like below

       .def _DSP28x_usDelay
       .sect "ramfuncs"

        .global  __DSP28x_usDelay
_DSP28x_usDelay:
        SUB    ACC,#1
        BF     _DSP28x_usDelay,GEQ    ;; Loop if ACC >= 0
        LRETR 

;There is a 9/10 cycle overhead and each loop
;takes five cycles. The LoopCount is given by
;the following formula:
;  DELAY_CPU_CYCLES = 9 + 5*LoopCount
; LoopCount = (DELAY_CPU_CYCLES - 9) / 5
; The macro DELAY_US(A) performs this calculation for you
;

For more clarification, please go to your target ...usDelay.asm file in you project.

-Aditya

[((5000000*1000)/(16.67))-(9)]/[5]= y =59988000

LoopCount 59988000 will be used in delay function to calculate 5 seconds delay.

That means, for your target,
For LoopCount = 1 will generate delay of (5/59988000 ) seconds. ie., Your target CPU will take (5/59988000 ) seconds  to execute one loop of Delay function.

Delay function execution of CPU cycles are known (Constant) only the LoopCount number will be different for different targets as well as different delay time provided by the user.

I hope you understand the calculation.

-Aditya

Also note that

Use one of the values provided, or define your own.  The trailing L is required tells the compiler to treat the number as a 64-bit value.

Example

#define CPU_RATE   16.667L   // for a 60MHz CPU clock speed (SYSCLKOUT)

-Aditya

Ok

still not understood sir..

Suppose if I want a delay of 1 Sec how do we calculate the passing value "uSec" into the function DELAY_US(uSec).

Probably this way I may understand quickly.

Hi,

DELAY_US(uSec)
Here the argument uSec will be in micro seconds.

For example, if you want 1 Sec delay then you need to pass the value of 1000000 micro seconds. ie., DELAY_US(1000000)
ie., 1 Sec = 1000000 micro seconds

For example you want 10 mSec delay then you should pass the value of 10000
ie., 10 mSec = 10000 micro seconds

For example you want 100 micro Sec (uSec) delay then you should pass the value of 100
ie., 100 uSec = 100 micro seconds

So the argument value should be in micro seconds to get the desired Delay.

-Aditya

Yes I have used Still.

The function is not at all working.
I am sharing the code snippet what I am using.

void Init(void)
{
InitSysCtrl();

InitEPwm1Gpio();
InitEPwm2Gpio();


DELAY_US(5000000);
GpioDataRegs.GPATOGGLE.bit.GPIO17 =1;


DisableDCDCPWM2();
EnableDCDCPWM1();

// DisableDCDCPWM1();
// DisableDCDCPWM2();
DINT;

InitPieCtrl();

IER = 0x0000;
IFR = 0x0000;

InitPieVectTable();

EALLOW;

PieVectTable.ADCINT1 = &adc1_Isr;
// PieVectTable.ADCINT2 = &adc2_Isr;
// PieVectTable.EPWM1_INT = &epwm1_isr;
// PieVectTable.EPWM2_INT = &epwm2_isr;
// PieVectTable.TINT0 = &cpu_timer0_isr;
// PieVectTable.TINT0 = &FiveSecTimerISR;
EDIS;


EALLOW;
SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0;
EDIS;

InitEPwm1();
InitEPwm2();
InitAdc1();
InitTimers();
InitAdc2();

EALLOW;
GpioCtrlRegs.GPAMUX2.bit.GPIO17 = 0; // 0=GPIO, 1=TZ3, 2=LINTX-A, 3=SPICLK-B
GpioCtrlRegs.GPADIR.bit.GPIO17 = 1; // 1=OUTput, 0=INput
GpioDataRegs.GPACLEAR.bit.GPIO17 = 1;

GpioCtrlRegs.GPAMUX1.bit.GPIO14 = 0; // 0=GPIO, 1=TZ3, 2=LINTX-A, 3=SPICLK-B
GpioCtrlRegs.GPADIR.bit.GPIO14 = 1; // 1=OUTput, 0=INput
GpioDataRegs.GPACLEAR.bit.GPIO14 = 1;
EDIS;



// Enable CPU INT3 which is connected to EPWM1-3 INT:
IER |= M_INT1;

EnablePWMInterrupts();


EALLOW;
PieCtrlRegs.PIECTRL.bit.ENPIE = 1; // Enable the PIE block
PieCtrlRegs.PIEIER1.bit.INTx1 = 1; // Enable INT 1.1 in the PIE for ADC
EDIS;


// Enable global Interrupts and higher priority real-time debug events:
EINT; // Enable Global interrupt INTM
ERTM; // Enable Global realtime interrupt DBGM
}

Hi,

I'm not able to find the repeatable call for below code in your shared code. So your GPIO17 is not toggling.

DELAY_US(5000000);
GpioDataRegs.GPATOGGLE.bit.GPIO17 =1;

Also note that, GpioDataRegs.GPATOGGLE.bit.GPIO17 =1 statement will do only change the state of GPIO17 once.

ie., if GPIO17 state is HIGH, then After executing GpioDataRegs.GPATOGGLE.bit.GPIO17 =1 statement, GPIO17 state will change from HIGH to LOW. If you call that statement again, then GPIO17 state will change from LOW to HIGH.

GPIO17 will not toggle continuously if you call this (GpioDataRegs.GPATOGGLE.bit.GPIO17 =1) statement once.

-Aditya